Honing tool

ABSTRACT

A honing tool having abrasive units adjustably mounted on a mandrel for honing cylindrical bores. The abrasive units comprise abrasive stones or sticks removably secured to carriers by wedge type clamps. Each carrier has a replaceable expansion rod or wire and also has a key providing a pair of retaining lips engageable in keyways on the mandrel to prevent the abrasive unit from separating from the mandrel when the mandrel is retracted.

United States Patent [1 1 [111 3,893,267

Swinehart et al. July 8, 1975 [541 HONING TOOL 2,580,328 12/1951 Sunnen51/338 Inventors; Clyde A. Swinehart, Unicio; Lyle Stanford Hasty,Erwin, both of Tenn.

Assignee: MWA Company, Owosso, Mich.

Filed: June 4, 1973 Appl. No.: 366,986

[52] U.S. Cl. 51/338 [51] Int. Cl. B2411 9/02 [58] Field of Search511338-352 [56] References Cited UNITED STATES PATENTS 1,797,837 3/1931Prange 51/339 2,195,055 3/1940 Wallace 51/338 Primary Examiner0thell M.Simpson Attorney, Agent, or FirmWhittemore, Hulbert & Belknap [57]ABSTRACT A honing tool having abrasive units adjustably mounted on amandrel for honing cylindrical bores. The abrasive units compriseabrasive stones or sticks removably secured to carriers by wedge typeclamps. Each carrier has a replaceable expansion rod or wire and alsohas a key providing a pair of retaining lips engageable in keyways onthe mandrel to prevent the abrasive unit from separating from themandrel when the mandrel is retracted.

3 Claims, 9 Drawing Figures SHEET I ll I s I,

rlll.

HONING TOOL BACKGROUND AND SUMMARY OF THE INVENTION This inventionconstitutes an improvement over the honing mandrel disclosed in US. Pat.No. 2.419.136. One of the advantages of the present invention is thatthe entire abrasive unit, including the carrier and ex pansion wire.does not have to be thrown away when the abrasive stones wear outbecause the abrasive stones are removably mounted on the carriers. In accordance with the preferred construction about to be described, a pairof abrasive sticks are mounted in spaced recesses on the carrier and areremovably held in place by a wedge type clamp. When the abrasive wearsout, it alone needs to be replaced, there being no need to discard thecarrier and the clamp. The expansion rod or wire and the key are alsoremovably secured to the carrier and likewise may be replaced ifnecessary.

As a further feature of the invention, the honing tool is designed topermit the use of abrasive sticks of varying length, depending upon therequirements of the particular operation and the length of abrasivesticks available. In addition, the honing tool about to be described hasbeen designed to afford more uniform abrasive wear and better cuttingaction.

In the drawings:

FIG. 1 is a side elevational view with parts broken away and in sectionof a honing tool embodying my invention.

FIG. 2 is an end view of the honing too] shown in FIG. 1, taken on theline 22 thereon.

FIG. 3 is a sectional view taken along the line 33 in FIG. 1.

FIG. 4 is a sectional view taken on the line 44 in FIG. I.

FIG. 5 is a longitudinal sectional view taken on the line 55 in FIG. 2.

FIG. 6 is a plan view of the carrier and expansion rod sub-assemblywhich form parts of an abrasive unit.

FIG. 7 is a sectional view taken on the line 7-7 in FIG. 6.

FIG. 8 is a longitudinal sectional view of the mandrel and is similar toFIG. 5 but with the abrasive units removed.

FIG. 9 is a sectional view taken on the line 99 in FIG. 8.

Referring now more particularly to the drawings. the honing tool isgenerally designated 10 and comprises an elongated mandrel 12 supportinga pair of abrasive units I4 for radial adjustment.

The abrasive units 14 each includes an elongated carrier 16, a pair ofelongated abrasive sticks IS, a wedge type clamp or plate for removablysecuring the abrasive sticks to the carrier, an expansion rod or wire 22removably secured to the carrier and a key 24 also removably secured tothe carrier.

The carrier has a generally flat radially outer surface 26 provided witha pair of longitudinally extending, laterally spaced, parallelsubstantially V-shaped recesses 28. The sides of each recess preferablyform a 90 angle as clearly seen in FIGS. 2, 3 and 7 to receive thecorner portions of the abrasive sticks 18 which are of rectangular crosssection throughout their length. The recesses 28 are turned to an anglesuch that the outer corners 19 of the sticks are presented to the borefor grinding. The adjacent surfaces 2I ofthe sticks 18 extending fromthe grinding corners I9 diverge in a radially outward direction. Theabrasive sticks 18 may extend throughout the full length ofthe carrieror two or more abrasive stick segments each of shorter length may beclamped end to end in each recess instead of one full length stick asmore fully described hereinafter.

The abrasive sticks 18 are removably secured to the carrier by a wedgetype clamp which may extend the full length of the carrier and is hereshown as being in the form of an elongated flat plate 20 having thelongitudinal parallel side edges 32 and 34 beveled as shown at the sameangle as the diverging surfaces 21 of the abrasive sticks for fullsurface contact therewith. The contact between the edges 32 and 34 ofplate 20 and the diverging surfaces 21 of the sticks provides a wedgetype clamp to more firmly hold the sticks in their recesses. The wedgeplate 20 is secured to the carrier by screws 36 which thread into holes37 in the carrier. Preferably the wedge plate 20 is of a width such thatwhen screwed down in contact with the abrasive sticks as shown in FIGS.2, 3 and 5, it is spaced from the top surface 26 of the carrier so thatthe full clamping pres sure of the plate 20 is applied to the abrasivesticks.

It is not necessary to use abrasive sticks which extend the full lengthof the carrier. One or more abrasive stick segments of less total lengthor the same total length as the carrier may be used if desired. Thedotted lines 38 in FIGS. 1 and 5 indicate the abutting ends of two abrasive stick segments one of which may be two inches long and the otherfour inches long, assuming a six-inch length carrier. Obviously otherlength segments may be employed.

It is also not necessary that the wedge plate 20 be a single memberextending the full length of the carrierv It too may comprise one ormore segments of less total length or the same total length as thecarrier. In FIGS. I and 5 the dotted lines 38 indicate the use of twowedge plate segments abutting end to end. Obviously more than two wedgeplate segments could be employed. On the other hand, if the abrasivesegments in the two recesses are shorter than the carrier, a singlewedge plate segment of the same length as the abrasive segments may beused.

The expansion rod or wire 22 is an elongated element having one endextending into an elongated longitudinally extending hole or socket 42in the rear end of the carrier. The rod end is removably held in thesocket by one of the screws 36 used to secure the wedge plate 20 to thecarrier. The other end of the expansion rod 22 terminates in a radiallyoutwardly extending part 44.

The carrier 16 has a generally flat radially inner surface 45 which isinclined away from the radially outer surface 26 from the rear end tothe front end of the carrier so that the carrier is thinner at the rearend than at the front end as shown. The inner surface 45 has atransverse recess 46 extending entirely across the full width of thecarrier in which an elongated plate or key 24 is secured. The ends ofthe key 24 project beyond the sides of the carrier to provide lips 50.The key 24 is removably secured in the recess 46 by screws 52.

The mandrel 12 is in the form of an elongated bar 49 having an elongatedhead 53 on which the abrasive units are mounted. The head has a pair ofelongated diametrically opposite channels 54 which extend the fulllength of the head 53. The bottom surfaces 58 of the channels are flatand tapered or sloped from the rear end to the front end of the mandrelhead in a direction toward the longitudinal axis of the head. Thechannels 54 are of the same width as the carriers to slidably re ceivethe carriers and it will be noted that the inner surface 45 of eachcarrier is sloped relative to the outer surface thereof at the sameangle as the bottom 58 of the channel 54 is sloped relative to thelongitudinal axis of the head. Accordingly. when the carriers are seatedin the channels as shown with the inner surfaces 45 in full surfacecontact with channel bottoms 58, the abrasive sticks extend parallel tothe mandrel axis and will remain parallel thereto throughout the rangeof radial adjustment of the carrier units which is accomplished bymoving the carriers lengthwise in the channels.

The mandrel head is also formed with a pair of grooves or keyways 62which extend laterally outwardly from the base of each channel 54. Thesegrooves extend rearwardly from the forward end of the mandrel. The lips50 of the key 24 of each carrier ex tend into the grooves 62 as shown inFIG. 2 to prevent the carriers from flying out or separating from themandrel when it is withdrawn from the work. The length of the grooves 62is sufficient to accommodate the full range of axial movement of thecarriers.

The mandrel head 53 has a longitudinally extending groove 70 in thebottom 58 of each channel 54. The groove extends from the front end ofthe head and terminates in the bar portion 49 of the mandrel 12 as seenin FIG. 1. The grooves 70 are of a size to slidably receive theexpansion rods or wires 22.

A suitable chuck 72 may be used to rotate the honing tool. The chuck 72has a driving sleeve 74 adapted to receive the end of the bar 49 of themandrel. The bar 49 can slide longitudinally in the sleeve 74 and has ascrew or other projection 76 extending into a longitudinal slot 78 inthe sleeve causing the bar 49 to rotate with the sleeve but permittingthe bar to slide longitudinally the length of the slot. The bar 49 ofthe mandrel may be connected to an axially shiftable adjusting member 80in the sleeve as by means of a bayonet type connection 82.

FIG. 1 shows the terminal parts 44 of the expansion rods 22 clampedagainst the end of the driving sleeve 74 by an i .urned annular flange84 on a cap 86 secured on the sleeve 74 as by threading. As seen in FIG.4, the flange 84 of the cap 86 has the diametrically opposite notches 88which, when the cap 86 is rotated counterclockwise from the FIG. 4position, will clear the terminal parts 44 of the expansion rods 22 topermit the expansion rods to be released.

It will be apparent that rotation of the chuck 72 will rotate the honingtool. The diameter of the honing tool may be varied by axially shiftingthe adjusting rod 80 to similarly move the mandrel causing the carriers16 to slide either up or down the sloped channels 54 in the mandrelhead.

The recesses 28 in the carriers 16 are turned to an angle such that thecorners of the rectangular sticks are presented to the bore forgrinding, resulting in better cutting action. More cutting edges arepresented to the work because several sticks of small cross section. inthis instance four, are employed rather than a smaller number, forexample one on each carrier. of larger cross section. The abrasivesticks wear uniformly and when they wear out they may be readilyreplaced by removing screws 36 and removing the clamping plate 20. Thecarriers themselves last indefinitely. Expansion rods or wires may alsobe replaced readily and without the need to change carriers by merelybacking off one of the screws 36. The carriers can of course hestandardized and used on other mandrels of different size. The retainingkey 24 can also be replaced by simply removing screws 52. The carriersalso permit infinite variation of abrasive stick length up to the lengthof the carrier itself.

What we claim as our invention is:

1. An abrasive unit adapted to be mounted on a honing tool mandrel.comprising an elongated carrier hav ing a pair of elongated laterallyspaced recesses in the outer face ofsaid carrier extending lengthwisethereof. an elongated abrasive stick of rectangular cross section ineach recess. said recesses being V-shaped and of right angle crosssection. each of said recesses being arranged to receive a corner of anabrasive stick and present the opposite corner thereof to the surface ofa cylinder bore for grinding. the adjacent surfaces of said sticksextending from the grinding corners thereof diverging in a radiallyoutward direction. means for releasably holding said abrasive sticks insaid recesses comprising a wedge plate removably secured to said carrierbetween said recesses in wcdging contact with said sticks. said wedgeplate having its opposite longitudinal edges inclined so as to havesubstantially full sur face-to-surface contact with said adjacentsurfaces of said sticks, an expansion rod. means releasably securingsaid expansion rod to one end of said carrier. a transverse recess inthe undersurface of said carrier at the opposite end thereof. anelongated transverse key disposed in said recess with its opposite endsprojecting beyond the sides of said carrier to provide retaining lipsfor retaining said carrier on the honing tool mandrel, and meansreleasably securing said key in said transverse recess.

2. An abrasive unit adapted to be mounted on a honing tool mandrel,comprising an elongated carrier having a pair of elongated laterallyspaced recesses in the outer face of said carrier extending lengthwisethereof, an elongated abrasive stick in each recess, means forreleasably holding said abrasive sticks in said recesses comprising awedge plate removably secured to said carrier between said recesses inwedging contact with said sticks. an elongated key. and means releasablysecuring said key to the front end of said carrier crosswise thereof andwith the opposite ends of said key projecting beyond opposite sides ofsaid carrier to provide retaining lips for retaining said carrier on thehoning tool mandrel.

3. An abrasive unit adapted to be mounted on a honing tool mandrel,comprising an elongated carrier having a pair of elongated laterallyspaced recesses in the outer face of said carrier extending lengthwisethereof, an elongated abrasive stick in each recess, means forreleasably holding said abrasive sticks in said recesses. an elongatedkey. and means releasably securing said key to said carrier crosswisethereof and with the opposite ends of said key projecting beyondopposite sides of said carrier to provide retaining lips for retainingsaid carrier on the honing tool mandrel.

1. An abrasive unit adapted to be mounted on a honing tool mandrel,comprising an elongated carrier having a pair of elongated laterallyspaced recesses in the outer face of said carrier extending lengthwisethereof, an elongated abrasive stick of rectangular cross section ineach recess, said recesses being V-shaped and of right angle crosssection, each of said recesses being arranged to receive a corner of anabrasive stick and present the opposite corNer thereof to the surface ofa cylinder bore for grinding, the adjacent surfaces of said sticksextending from the grinding corners thereof diverging in a radiallyoutward direction, means for releasably holding said abrasive sticks insaid recesses comprising a wedge plate removably secured to said carrierbetween said recesses in wedging contact with said sticks, said wedgeplate having its opposite longitudinal edges inclined so as to havesubstantially full surface-to-surface contact with said adjacentsurfaces of said sticks, an expansion rod, means releasably securingsaid expansion rod to one end of said carrier, a transverse recess inthe undersurface of said carrier at the opposite end thereof, anelongated transverse key disposed in said recess with its opposite endsprojecting beyond the sides of said carrier to provide retaining lipsfor retaining said carrier on the honing tool mandrel, and meansreleasably securing said key in said transverse recess.
 2. An abrasiveunit adapted to be mounted on a honing tool mandrel, comprising anelongated carrier having a pair of elongated laterally spaced recessesin the outer face of said carrier extending lengthwise thereof, anelongated abrasive stick in each recess, means for releasably holdingsaid abrasive sticks in said recesses comprising a wedge plate removablysecured to said carrier between said recesses in wedging contact withsaid sticks, an elongated key, and means releasably securing said key tothe front end of said carrier crosswise thereof and with the oppositeends of said key projecting beyond opposite sides of said carrier toprovide retaining lips for retaining said carrier on the honing toolmandrel.
 3. An abrasive unit adapted to be mounted on a honing toolmandrel, comprising an elongated carrier having a pair of elongatedlaterally spaced recesses in the outer face of said carrier extendinglengthwise thereof, an elongated abrasive stick in each recess, meansfor releasably holding said abrasive sticks in said recesses, anelongated key, and means releasably securing said key to said carriercrosswise thereof and with the opposite ends of said key projectingbeyond opposite sides of said carrier to provide retaining lips forretaining said carrier on the honing tool mandrel.